In four cross-linguistic experiments comparing French and Japanese hearers, we found that the phonotactic properties of Japanese (very reduced set of syllable types) induce Japanese listeners to perceive "illusory" vowels inside consonant clusters in VCCV stimuli. In Experiments 1 and 2, we used a continuum of stimuli ranging from no vowel (e.g. ebzo) to a full vowel between the consonants (e.g. ebuzo). Japanese, but not French participants, reported the presence of a vowel [u] between consonants, even in stimuli with no vowel. A speeded ABX discrimination paradigm was used in Experiments 3 and 4, and revealed that Japanese participants had trouble discriminating between VCCV and VCuCV stimuli. French participants, in contrast had problems discriminating items that differ in vowel length (ebuzo vs. ebuuzo), a distinctive contrast in Japanese but not in French. We conclude that models of speech perception have to be revised to account for phonotactically-based assimilations.

A parametric study of so-called "super growth" of single-walled carbon nanotubes (SWNTs) was done by using combinatorial libraries of iron/aluminum oxide catalysts.Millimeter-thick forests of nanotubes grew within 10 min, and those grown by using catalysts with a thin Fe layer (about 0.5 nm) were SWNTs. Although nanotube forests grew under a wide range of reaction conditions such as gas composition and temperature, the window for SWNT was narrow. Fe catalysts rapidly grew nanotubes only when supported on aluminum oxide. Aluminum oxide, which is a well-known catalyst in hydrocarbon reforming, plays an essential role in enhancing the nanotube growth rates.

The effectiveness of a high variability identification training procedure to improve native Japanese identification and production of the American English (AE) mid and low vowels /ae/, /A/, /2/, /O/, /Ç/ was investigated. Vowel identification and production performance for two groups of Japanese participants was measured before and after a 6-week identification training period. Recordings were made of both group's pre-/posttraining vowel productions of the five vowels, which were evaluated by a group of native AE listeners using a five-alternative, forced-choice identification task and by an acoustic analysis of the vowel productions. The overall results confirmed that the identification performance of the experimental (trained) participants improved after identification training with feedback and that the training also had a positive effect on their production of the target AE vowels. When learning a second or foreign language (L2), adults typically have difficulty mastering certain phonemic contrasts in the target language (Best, 1995;MacKain, Best, & Strange, 1981). As language-specific perceivers, adults' perception of speech is attuned to contrastive elements that serve to distinguish native phones during first or native language (L1) acquisition. It can be a challenge for listeners to accurately distinguish between sounds in the L2, or between L1 and

When presented with stimuli that contain illegal consonant clusters, Japanese listeners tend to hear an illusory vowel that makes their perception conform to the phonotactics of their language. In a previous paper, we suggested that this effect arises from language-specific prelexical processes (Dupoux, Kakehi, Hirose, Pallier & Mehler, 1999). The present paper assesses the alternative hypothesis that this illusion is due to a "top-down" lexical effect. We manipulate the lexical neighborhood of non-words that contain illegal consonant clusters and show that perception of the illusory vowel is not due to lexical influences. This demonstrates that phonotactic knowledge influences speech processing at an early stage.

Our group recently reproduced the water-assisted growth method, so-called "SuperGrowth", of millimeter-thick single-walled carbon nanotube (SWNT) forests by using C2H4/H2/H2O/Ar reactant gas and Fe/Al2O3, catalyst. In this current work, a parametric study was carried out on both reaction and catalyst conditions. Results revealed that a thin Fe catalyst layer (about 0.5 nm) yielded rapid growth of SWNTs only when supported on Al2O3, and that Al2O3 support enhanced the activity of Fe, Co, and Ni catalysts. The growth window for the rapid SWNT growth was narrow, however. Optimum amount of added H2O increased the SWNT growth rate but further addition of H2O degraded both the SWNT growth rate and quality. Addition of H2 was also essential for rapid SWNT growth, but again, further addition decreased both the SWNT growth rate and quality. Because Al2O3 catalyzes hydrocarbon reforming, Al2O3 support possibly enhances the SWNT growth rate by supplying the carbon source to the catalyst nanoparticles. The origin of the narrow window for rapid SWNT growth is also discussed.